This work is devoted to estimating the individual return to worker’s professional training. The research is based on the personnel records of Russian metallurgical enterprise (2006–2010). The main factors that distinguish this paper from others are the following: (I) We focused on the...

Inference for estimates of treatment effects with clustered data requires great care when treatment is assigned at the group level. This is true for both pure treatment models and difference-in-differences regressions. Even when the number of clusters is quite large, cluster-robust standard...